Flabellinid Nudibranch

Photo: Stefan · CC BY-NC

The vivid purple and cerise Flabellina affinis nudibranch appears in abundance at El Ancón between February and May, crawling across hydroids on the rocky margins adjacent to the meadow in search of its cnidarian prey. Its presence is a reliable indicator of the park's excellent water quality, as nudibranchs are highly sensitive to sedimentation and chemical contamination. Egg masses — delicate white spirals attached to hydroid stalks — are often found close to feeding individuals and represent some of the most photogenic macro subjects in European diving.